1. Field of the Disclosure
This specification relates to power line communication, and more particularly, a repeater for power line communication and a repeating method thereof.
2. Background of the Disclosure
Power line communication is a type of communication method for transmitting data by using existing power lines, which are previously installed to supply an electric power, without installing an additional communication line for the data transmission.
The power line communication is considered as a communication method appropriate to be applied to various industrial fields, such as home networking, factory automation, telemetering and the like, in view of several advantages of low investment costs, and simplified communication in a manner of connecting a power line modem into a socket installed on a wall of a building.
The power line communication is configured by connecting a power line communication concentrator and a plurality of power line communication terminals to a power line, such that the power line communication concentrator and the plurality of power line communication terminals can receive operation power through the power line.
Also, the power line communication concentrator and the plurality of power line communication terminals mutually transmit a data including control signals, through the power line.
When the power line communication concentrator and the plurality of power line communication terminals connected through the power line perform communication, a communication-available distance is limited due to many noise signals existing along the power line, line resistance of the power line, interference phenomenon, and the like.
Therefore, to improve a communication environment of a communication-unavailable section of the power line communication, a power line communication terminal which is located at an end of a communication-available section is set to execute a repeating function.
The power line communication terminal set to perform the repeating function decides (determines) whether or not data (data packet) received from upper communication end (power line communication concentrator) or lower communication end (another power line communication terminal) is data to be repeated, and then repeats the received data when it is determined as the data to be repeated.
That is, when data received from the power line communication concentrator or another power line communication terminal is data to be repeated, the power line communication terminals which have been set to execute the repeating function restore an electric power level of the received data packet to its original electric power level, output the level-restored data packet through the power line and then repeat the corresponding data packet.
Korean Patent Application Nos. 2010-0015704 and 2010-0074610, which are the prior arts of the present disclosure, disclose a repeater and repeating method for power line communication.
Korean Patent Application No. 2010-0015704 discloses a repeater for power line communication and a repeating method thereof, in which data which has been repeated by power line communication terminals set as repeaters is not repeated again.
Meanwhile, in Korean Patent Application No. 2010-0074610, power line communication terminals which have been set to execute a repeating function for repeating a data packet previously add addresses, respectively, among a plurality of power line communication terminals which are connected to a power line to execute power line communication with a power line communication concentrator. Then, when a recipient address of the received data packet is the same as the pre-stored address, the received data packet is repeated.
However, when the power line communication terminals each set to execute the repeating function are connected to the power line in those prior arts, the plurality of power line communication terminals each having the repeating function receive the same data packet and simultaneously repeat the data packet.
Also, a ping-pong phenomenon that a power line communication terminal having the repeating function repetitively repeats the same data packet is caused in the prior arts.
This inevitably results in a data packet loss due to a data packet collision, non-smooth power line communication due to communication failure, and degradation of communication reliability and communication speed.